施氮量对强筋小麦氮素积累和氮肥农学利用效率的影响

为探究冀东平原强筋小麦高产优质高效的最佳施氮量,在大田选用石优20号和中麦998两个强筋小麦品种,设置施氮量0 (N_0)、180 (N_1)和240 (N_2)kg·hm~(-2),研究了施氮量对强筋小麦氮素积累、转运和氮肥农学利用效率的效应。结果表明,小麦花前氮素积累量占成熟期植株地上部总氮素积累量的59%～66%,花后占34%～41%。随施氮量增加,小麦植株花前氮素积累量和转运量均提高,叶是花前氮素积累和转运的主要器官。小麦籽粒灌浆过程中,营养器官的氮素积累量逐渐下降,籽粒氮素积累量逐渐提高,营养器官氮素转运高峰与籽粒氮素积累高峰一致,石优20号为花后14～21d,中麦998为花后7～21d。施氮量从180 kg·hm~(-2)增加到240kg·hm~(-2),石优20号和中麦998的产量分别提高了6.10%和7.58%,籽粒蛋白质含量分别提高了3.68%和3.73%,而氮肥农学利用效率分别降低了25.68%和23.93%。综上所述,促进花前氮素的积累和转运可提高强筋小麦蛋白质含量;适当减少施氮量可实现强筋小麦的提质增效。本试验条件下,冀东平原强筋小麦生产的适宜施氮量为180kg·hm~(-2)。

Effect of Nitrogen Rate on Nitrogen Accumulation and Agronomic Efficiency in Strong Gluten Wheat

To explore the optimum nitrogen(N) rate on higher yield, quality and efficiency of strong gluten wheat in the Eastern Hebei Plain, two strong gluten wheat varieties(Shiyou 20 and Zhongmai 998) were selected and treated with three N fertilizer levels(0, 180 and 240 kg·hm^-2), to study the effect of N rate on the accumulation and translocation of N and the agronomic efficiency of N (NAE). The results showed that the N accumulation before anthesis accounted for 59.00%-66.00% of the total N rate above ground in mature period and 34.00%-41.00% after anthesis. With the increase of N application, both the N accumulation before anthesis and the N translocation after anthesis were increased. Leaves were the main organs of N accumulation before anthesis and N translocation after anthesis. In the process of grain filling, the accumulation of N in vegetative organs decreased gradually, and the accumulation of N in grains increased gradually. The peak of N translocation in vegetative organs was the same as that in grains, 14-21 days after anthesis for Shiyou 20, and 7-21 days after anthesis for Zhongmai 998. The yield of Shiyou 20 and Zhongmai 998 increased by 6.10% and 7.58%,respectively, the grain protein content increased by 3.68% and 3.73%, while the agronomic efficiency of N fertilizer decreased by 25.68% and 23.93%, respectively. In conclusion, to promote the accumulation of N before anthesis and translocation after anthesis can improve the protein content of strong gluten wheat; to reduce the amount of N application properly can achieve the improvement of quality and efficiency of strong gluten wheat. Under the condition of this experiment, the suitable amount of N rate for the production of strong gluten wheat in the East of Hebei Plain was 180 kg·hm^-2.